diff --git a/contrib/import-checker.py b/contrib/import-checker.py
--- a/contrib/import-checker.py
+++ b/contrib/import-checker.py
@@ -30,6 +30,7 @@
     'mercurial.i18n',
     'mercurial.interfaces',
     'mercurial.node',
+    'mercurial.pycompat',
     # for revlog to re-export constant to extensions
     'mercurial.revlogutils.constants',
     'mercurial.revlogutils.flagutil',